This may help - I just got this from a friend. http://jeremy.zawodny.com/blog/archives/000203.html
--Joe -- Joe Stump <[EMAIL PROTECTED]> http://www.joestump.net "Label makers are proof God wants Sys Admins to be happy." -----Original Message----- From: Matthias Trevarthan [mailto:[EMAIL PROTECTED] Sent: Friday, March 14, 2003 7:16 AM To: [EMAIL PROTECTED] Subject: FreeBSD + MySQL bottleneck Howdy list, I run MySQL 3.23.54 with FreeBSD 4.6-RELEASE. We recently had a BBS get hammered by a lot of concentrated traffic. I currently run a 'mysql-optimize.sh' script from cron on Wednesday and Sunday that executes: ${bindir}/myisamchk -i -r --check --sort-index --analyze ${datadir}/*/*.MYI ${bindir}/isamchk -i -r --analyze --sort-index ${datadir}/*/*.ISM This works great to keep my databases lean and mean for normal server load and traffic, but this last hit was just too much. The server was bottlenecked somewhere. Problem was, I couldn't figure out where! I'm running SCSI 160 disks in a Raid config, with a dual 1GHZ PIII and 1G of SDRAM. I'd think that setup would be able to handle some pretty killer loads... Anyway, I ran 'top', and MySQL was turning about 97% processor utilitzation on one processor. It said I still had 128M of free ram left (and my MySQL tables are all under 10M). And I was only using 3% swap, which is normal because I run phpa_accelerator. Also, 'mysql> show status;' showed that I only had about 25 threads open at a time. And it also said I had 82 tables open. My T1s were NOT maxed out. They weren't even half full, and besides: I accessed the BBS from our 100Mb switch, and it was still dog slow (20-30 seconds for a page load), which means it was purely a bottleneck in my machine. So, my questions are these: --------------------------- Can any experienced MySQL-FreeBSD admins out there give me some pointers for identifying bottlenecks? Specifically, I don't know how to determine if my disks were being maxed out. Could someone give me some pointers? And also, from 'show status', is the number of 'threads' directly related to the specific number of MySQL socket connections? (I have MySQL setup to allow up to 200 and I wasn't even getting over 30 from 'netstat | grep -i mysql') Any help would be appreciated! Thanks! Matthias --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
